Good morning. This is Doug Chabot with the Gallatin National Forest Avalanche Advisory issued on Tuesday, January 15 at 7:30 a.m. Today’s advisory is sponsored by Helio Collective and Knapp Sacks. This advisory does not apply to operating ski areas.
On a northwest flow Bridger Bowl picked up six inches last night with four inches around Big Sky and 1-3 inches everywhere else. Mountain temperatures are near ten degrees, except around Cooke City and West Yellowstone where they are minus five. Winds are west to northwest at 20-35 mph. High pressure shoves its way in this afternoon and will stay for a few days. An additional trace to one inch may fall this morning as temperatures warm into the high teens under clearing skies. Winds will remain steady at 20-30 mph out of the northwest.
Bridger Range Madison Range Gallatin Range
Lionhead area near West Yellowstone Cooke City
Yesterday, I skied into the Hebgen Lake area near West Yellowstone. I was very curious about the stability since Karl and I found unstable snow six inches under the surface last Wednesday right before the storm and avalanche warning. I found the weak crystals of small, sugary facets buried under ten inches of snow, but the layer was not widespread; it was confined to mostly southeast facing slopes. I had to dig three snowpits to find it. We got low scores (ECTP11) in our stability tests (video), but did not get any cracking or collapsing as we toured
Over the weekend Eric skied into Bacon Rind (video, photo) and he and Mark rode into Lionhead. On both field days they did not find widespread instability. There was minimal avalanche activity and snowpits were mostly stable. On Sunday, a guide at Ace Powder Guides noted a larger slide on an east facing slope in Red Canyon in the southern Madison Range, but given the avalanche warning on Friday this was not unusual. In Teepee Basin he got low test scores on the facets buried by last week’s storm.
New snow last night came in with west to northwest winds. Wind drifts will be easily triggered today, most likely near the ridgetops. A few shallow wind drifts were cut yesterday by ski patrols at Bridger and Big Sky. Wind loads are everywhere, while facets are buried deepest in the southern ranges. This layer is also found in the mountains around Big Sky and Bozeman, but is least developed around Cooke City.
Travel advice is not very complicated today: stay off of wind-loaded slopes and avoid slopes that harbor the weak, shallowly buried, unbonded facets. Find it with a quick swipe of the shovel followed by a simple compression test to determine stability. It took me three pits to find it yesterday which is a reminder why we don’t call it quits after one pit. If we know weak snow exists but stop hunting after not finding it the first time, we will eventually get spanked.
For today, wind-loaded slopes have a CONSIDERABLE avalanche danger while all other terrain has a MODERATE danger.
I will issue the next advisory tomorrow morning at 7:30 a.m. If you have any snowpack or avalanche observations drop us a line at mtavalanche@gmail.com or call us at 587-6984.
Tomorrow, January 16, 7:00 p.m. “The Sidecountry is Backcountry” at MSU’s Procrastinator Theater in Bozeman, a free 1-hour presentation.
Saturday, January 19, Rescue Clinic for Snowmobilers in Cooke City starting at Cooke City Motorsports. This 6 hour clinic teaches how to use avalanche rescue gear and perform an avalanche rescue. Registration is required. For more info and to sign up, visit: https://www.ticketriver.com/event/4980-companion-rescue-clinic-for-snowmobilers
Saturday, January 19, 6 -7 p.m., 1-hour Avalanche Awareness at the Cooke City Community Center.
Wednesday, Thursday, and Saturday, January 23, 24, and 26. MSU Introduction to Avalanches with Field Course. Wed and Thurs evenings and all day Saturday. For more information and to register, visit: https://www.ticketriver.com/event/4970-introduction-to-avalanches-w--field-course